Highlights from Obama's Paris speech

Here are the top quotes from US President Barack Obama news conference Tuesday, held on the sidelines of the UN climate summit in Paris.

- Climate change threat-

If we let the world keep warming as fast as it is, and sea levels rising as fast as they are, and weather patterns keep shifting in more unexpected ways, then before long we are going to have to devote more and more and more of our economic and military resources not to growing opportunity for our people but to adapting to the various consequences of a changing planet.

I am optimistic. I think we are going to solve it. I think the issue is just going to be the pace and how much damage is done before we are able to fully apply the brakes.

The thing about human ingenuity is, it responds when it gets a strong signal of what needs to be done.

I have long believed the most elegant way to drive innovation and reduce carbon emissions is to put a price on it.

- Republican attitudes -

American leadership involves not just playing to the American constituency back home... your credibility and America's ability to influence events depends on taking seriously what other countries care about.

- Strikes against IS -

The pace of air strikes is not constrained by the planes or militaries that we have. The pace has been dictated by how many effective targets do we have, and our intelligence continues to improve.

- Russia's strategy in Syria -

I think it is possible over the next several months that we both see a shift in calculation in the Russians and a recognition that it is time to bring the civil war in Syria to a close. It is not going to be easy. Too much blood has been shed.

I think Mr Putin understands that, with Afghanistan fresh in the memory, for him to simply get bogged down in an inconclusive and paralysing civil conflict is not the outcome that he's looking for.

- Removing Assad -

I consider somebody who kills hundreds of thousands of his own people illegitimate. But regardless of the moral equation, as a practical matter it is impossible for Mr Assad to bring that country together, and to bring all the parties into an inclusive government

- Planned Parenthood shooting -

We are rightly determined to prevent terrorist attacks wherever they occur... and yet in the United States we have the power to do more to prevent what is just a regular process of gun homicides.